In vivo assessment of the host reactions to the biodegradation of the two novel magnesium alloys ZEK100 and AX30 in an animal model

• Main Authors: Huehnerschulte Tim, Reifenrath Janin, von Rechenberg Brigitte, Dziuba Dina, Seitz Jan, Bormann Dirk, Windhagen Henning, Meyer-Lindenberg Andrea
• Format: Article
• Language: English
• Published: BMC 2012-03-01
• Series: BioMedical Engineering OnLine
• Subjects: Magnesium; In vivo; Biocompatibility; Degradation; μ-computed tomography; Histology
• Online Access: http://www.biomedical-engineering-online.com/content/11/1/14

<p>Abstract</p> <p>Background</p> <p>Most studies on biodegradable magnesium implants published recently use magnesium-calcium-alloys or magnesium-aluminum-rare earth-alloys.</p> <p>However, since rare earths are a mixture of elements and their toxicity is unclear, a reduced content of rare earths is favorable. The present study assesses the in vivo biocompatibility of two new magnesium alloys which have a reduced content (ZEK100) or contain no rare earths at all (AX30).</p> <p>Methods</p> <p>24 rabbits were randomized into 4 groups (AX30 or ZEK100, 3 or 6 months, respectively) and cylindrical pins were inserted in their tibiae. To assess the biodegradation μCT scans and histological examinations were performed.</p> <p>Results</p> <p>The μCT scans showed that until month three ZEK100 degrades faster than AX30, but this difference is leveled out after 6 months. Histology revealed that both materials induce adverse host reactions and high numbers of osteoclasts in the recipient bone. The mineral apposition rates of both materials groups were high.</p> <p>Conclusions</p> <p>Both alloys display favorable degradation characteristics, but they induce adverse host reactions, namely an osteoclast-driven resorption of bone and a subsequent periosteal formation of new bone. Therefore, the biocompatibility of ZEK100 and AX30 is questionable and further studies, which should focus on the interactions on cellular level, are needed.</p>